Markus Kerber, director general of the BDI (Bundesverband der Deutschen Industrie – the Federal Association of German Industry), said: “We need to maintain economic relations between the EU and the UK as close as possible, but this must not happen at the expense of the integrity of the Single Market. Cherry picking between the four Single Market freedoms is not an option.”

European companies echoed calls for an open negotiating process which reduces complications for businesses in the UK and the EU, according to the BDI.

Kerber said: “European companies present in the UK, either through deep trading relations or through direct investment, are highly concerned about the process going forward. Their concerns all concentrate on a need to guarantee legal certainty, on making the exit-strategy and procedure more transparent, and on minimizing adverse effects on their businesses during all stages of the exiting process.”

However, freedom of movement is one of the four pillars of the Single Market. European diplomats – including European Council president Donald Tusk – have stuck to the line that the UK cannot sacrifice any of the pillars without leaving the Single Market.